A known opening and closing control system for opening-closing member of the vehicle (opening-closing member) is disclosed in Japanese Patent Laid-Open Publication No. 2-114071. The system includes a hinge arm for closing and opening the opening-closing member relative to the vehicle, a motor for activating the hinge arm, and a connecting device for connecting the hinge arm member and a cable which is rotated by the motor. The connecting device includes a mechanism for disconnecting from the hinge arm side when the cable applies a tensility to the connecting device. According to the know opening and closing control system, an load equal to or more than a predetermined amount cannot be applied to the opening-closing member even if a driver applies a load to the opening-closing member for interfering the opening-closing member's closing-operation while the motor rotates for closing the opening-closing member due to the mechanism of the connecting device disconnecting from the connecting device.
In this configuration, once the connecting device disconnects the motor side from the hinge arm side, they need to be connected again.
To prevent the opening-closing member from being applied a load equal to or more than the predetermined amount without using the connecting device, a clutch mechanism may be provided between an actuator and the opening and closing mechanism as disclosed in Japanese Patent Laid-Open Publication No. 2001-277853 kouhou. In this configuration, an engaging force of the clutch mechanism is reversibly controlled, so that the actuator and the opening and closing mechanism are engaged releasing the torque transmission (sliding the clutch mechanism), not completely disengaging the actuator from the opening and closing mechanism (not completely engaging or disengaging) as described above. As a result, the reconnecting operation is not needed after the connecting device disconnects the motor from the hinge arm as described in Japanese Patent Laid-Open Publication No. 2-114071 kouhou. However, if the opening and closing mechanism is adapted to change the supporting force of the opening-closing member based on the opening and closing angle of the opening-closing member, the clutch mechanism can slide only in case that a load which is equal to or more than the supporting force is applied. In other word, the load required for sliding the clutch mechanism changes depending on the opening and closing angle of the opening-closing member. Thus, when a certain load is applied to the opening-closing member at which the supporting force of the opening-closing member is large, the clutch can be slid if the load is equal to or less than the supporting force. Furthermore, the opening-closing member etc. may be damaged due to the load applied to the opening-closing member.